Choosing a mate is one of the most important decisions an animal can make. The fitness costs and benefits have been analyzed extensively in the context of sexual selection. The neural and hormonal bases of mate choice have provided insights into how animals make such decisions. Less attention has been given to the higher-level cognitive processes involved. The assumption that animals choose mates predictably and rationally is often violated. I will review studies in which cognitive analyses suggest that mate choice decisions are more complex than they might seem.